The Spin Right Spinner is an innovative tool endorsed by three MLB pros to help you develop pro-level throwing power. Dr. Tom House, Marvin Freeman, and Lean Lawrence have each put their stamp of approval on this product to help you maximize your performance potential. Performance Pitch design is an indispensable training tool for all athletes, providing advanced throwing mechanics without putting stress on your arm. Its innovative design allows you to feel the correct pitching motion and improve your mechanics with improved accuracy and speed.